Pencil-lead



(No Model.)

J. A. 000K. PENCIL LEAD.

No. 524,757. Patented Aug. 211, 1894.

645136455 (D'gyeg 2&7.

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UNITE STATES i PATENT OFFICE.

JOHN A. COOK, OF BUFFALO, NEW YORK.

PENCIL-LEAD.

SPECIFICATION forming part of Letters Patent No. 524,757, dated August21, 1894. Application filed December 22,1893. Elerial No. 494,390. (Nomodel.)

To all whom it may concern:

Be it .known that 1, JOHN A. COOK, a citizen of the United States,residing at Buffalo, in the county of Erie and State of New York, haveinvented certain new and useful 1m provements in Pencil-Leads; and I dohereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same, reference being bad to theaccompanying drawings, and to figures of reference marked thereon, whichform a part of this specification.

My invention relates to certain improvements in pencil-leads of thatparticular class which are adapted for adjustable insertion betweenholding-jaws carried by the shell or casing of the pencil, or which areadapted to be fed forward, as desired, by any suitable means as theirends are worn away.

The primary object of my invention is to provide a self-sharpening leadof the above mentioned type with which a fine line can be made at alltimes without the necessity of cutting or trimming the exposedextremity.

With this end in view, as well as others, which will be distinctlyhereinafter stated, my invention consists broadly of a hollowpencil-lead.

I will now proceed to minutely describe the manner in which I havecarried out my invention and then claim what I believe to be novel.

In the drawings, Figure 1 is a side view of a pencil containing myimproved lead. Fig. 2 is a perspective view of my improved lead removedfrom the pencil, and Fig. 3 is an end view of the same.

Referring to the drawings, 1 is the shell or casing of the pencil and 2.2. are the protruding ends of the holding-jaws, between which the leadis adj ustably held.

3 is the protruding end of a spring-pressed plunger for temporarilyseparating the holding-jaws in order that the lead may be properlyadjusted in the holding-jaws as its end becomes worn away.

I have shown the style of pencil just outlined simply to illustratebroadly that class to which my improved form of lead is or can beapplied it being understood that it is applicable to any and all formsof pencils in which the lead is either adj ustably held or fed forwardas desired by any suitable means.

4 is my improved form of lead which is preferably of hollow cylindricalconfiguration, as shown, although other hollow forms might beadvantageously employed such as tubes which are triangular, square,hexagonal, &c., in transverse section, the cylindrical or circular formbeingbest adapted however, for universal use. The material employed inits construction is'the same as is now used in the manufacture ofordinary leads. The wall of this lead tube 4: is preferably thin inorder that a correspondingly fine line may be made upon the paper as itsedge is brought in contact therewith in the act of writing or drawing.

My improved lead has, as shown, acircumferential edge and, in the act ofwr1t1ng,th1s edge is worn away uniformly around its entire circumferenceas the pencil is naturally turned or shifted in the hand, thus becomingself-sharpening simply from actual use. This results in, not only savingthetime, now thrown away in sharpening the points of the ordinary leadsbut in utilizing every atom of the lead thus preventing the veryconsiderable waste of material involved in the sharpening process.

Less material is required in the formation of my improved form of lead,than in those now in common use and as there is no waste, common tosharpening, the life of the lead 1s correspondingly prolonged.

Another important feature due to my 1mproved structural formation, isits increased strength, not only along its entire body, but especiallyat its point of contact with the paper, as the absence of any abrupttaper, WlllGll is common in sharpened leads, greatly lessens theliability of breakage at the contacting end. In fact it requires anextraordinary pressure to fracture the exposed end of my improved formof lead.

I claim- 1. A hollow pencil-lead substantially as and for the purposestated.

2. A pencil-lead of hollow cylindrical configuration substantially asand for the purpose stated.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

I JOHN A. COOK. Witnesses:

O. E. HoDDIoK, W. T. MILLER.

